WASHINGTON
— President Bush has long expressed skepticism about committing US military forces as peacekeepers overseas.

Now, on the eve of his first presidential visit to Africa, he appears willing to do just that in a corner of the world few Americans can point to on a map. But if US forces do wind up in Liberia - a West African nation at a crucial moment in its 13-year civil war - the administration can frame its involvement in a way that limits the impression that the United States is becoming sheriff of the world, analysts say.

First, in recent days top White House officials have raised the US's unique historical connection to Liberia as a possible justification for sending in a small force. Liberia was founded in the 19th century by freed American slaves. By highlighting a link that no other country has, the administration can claim it has set no precedent for involvement in other remote countries.

Second, US officials have made clear that if the United States does send troops to Liberia, the size and scope of their mission will be limited. Reports indicate that between 500 and 2,000 troops would go, and they would stay for a short period of perhaps several months. While remaining under US command, they would work with peacekeepers from other African countries.

But in the larger scheme, the fact that the Bush administration may send peacekeeping forces to Liberia represents how much the world has changed since the 2000 presidential campaign. Then, Bush pooh-poohed the concept of nation-building and laid out three requirements for the use of US troops abroad: involvement of vital US interests, a clear mission, and an obvious exit strategy.

Those three criteria hold, administration officials say, but the definitions have evolved.

Since Sept. 11, 2001, the US has had to come to grips with the existence of "failed states," where massive instability leaves a nation open to a major terrorist presence. In a press conference last Friday, national security adviser Condoleezza Rice raised that issue in connection with Liberia. "The president does believe that Liberia and the stability of West Africa [are] important to US interests," she said.

In addition to the humanitarian situation there, she continued, "we've also recognized since 9/11 that one wants to be careful about permitting conditions of failed states" that could lead to "greater sources of terrorism."

Pentagon officials have reportedly reacted negatively to sending troops to Liberia, arguing that the US military already has enough on its plate, including major operations in Iraq and Afghanistan. But the Pentagon's European Command is nevertheless drawing up different options for the president. Sunday, a team of US military experts flew from Germany to Liberia to assess conditions. On his own trip, Bush will not visit Liberia. He travels to Botswana, South Africa, Nigeria, Senegal, and Uganda.

In certain ways, the Iraq intervention is almost forcing Bush's hand with Liberia, says Peter Singer, a foreign-policy fellow at the Brookings Institution and an expert on peacekeeping.

"On a number of levels where [the US] justified intervening in Iraq, Liberia either equals or beats it," says Mr. Singer.

On the humanitarian front, the war in Liberia has killed more than a quarter-million people and chased out 2 million more as refugees. On the regional front, Liberian President Charles Taylor is seen as a destabilizing presence, having helped launch wars in three neighboring countries. On the energy front, there is an oil dimension to the Liberia story: One-fifth of US oil comes from West Africa.

And on the question of the US's relations with the United Nations, which have been strained, going along with a peacekeeping operation in Liberia could be helpful - and even foster more goodwill with US operations in Iraq. UN diplomats have cited Britain and France's decision to send troops to former West African colonies Sierra Leone and Ivory Coast as heightening the US responsibility to Liberia.

Even if the atmospherics have changed, the argument over whether the US should intervene in Liberia is not new. "The State Department has been arguing we ought to do something, and the Pentagon has been saying 'not with our troops,'" says Dennis Jett, former deputy US ambassador to Liberia. "This argument has been going on and off with Liberia since the war started in 1989."

"It's an accident of timing that's brought it to the fore," says Ambassador Jett, now dean of the International Center at the University of Florida at Gainesville. "I'd be surprised if we sent in a thousand troops. Maybe we will, but only for a short term, to stabilize the situation, then get out."

Bush has structured his demands in a way that he can avoid sending troops altogether. In recent days, he's called on President Taylor several times to leave the country, saying he won't send peacekeepers if Taylor is still there. Taylor says he won't leave until peacekeepers are there to restore order. Taylor has a disincentive to leave, since he is under indictment for war crimes by a UN court in Sierra Leone.

Anthony Cordesman, an analyst at the Center for Strategic and International Studies, is skeptical about sending troops to Liberia. "There's no way to know what level of violence you'll encounter, and no way to know how long it lasts," he says. "Far too many of these missions seem to extend indefinitely without benefit or outcome."

Mr. Cordesman also doesn't see how US involvement in an international peacekeeping force in Liberia makes the US any more of a "global policeman" than it already is.